Generator Power and FAST version 7.0


I am conducting an analysis on the NREL 5MW model with Matlab/Simulink. I am using Simulink to control blade pitch and gen torque. Gen power is also calculated in Simulink using GenSpeed and GenTq. I am currently using FAST v6.02c-jmj and everything is working fine. But am now converting to FAST v7.0 to take advantage of the memory leak fix. As I understand, I do not need to change any of my input files.

To get started, I am comparing some baseline data. The only files I replaced are FAST_SFunc.mexw32 and Read_FAST_Input.m. When comparing the .out files, everything looks very good, except for GenPwr. For some reason, GenPwr from v7.0 is 100 times the value from v6.02. I did not change any calculations in Simulink.

Am I missing something?


Hi, Scott.

GenPwr is an input (from Simulink) to the FAST S-Function block. It sounds like you are calculating this from GenSpeed and GenTq? Are you applying the generator efficiency, GenEff, in this calculation?

The new Matlab script stores some extra variables from the FAST input file (e.g., GenEff), which we were going to use for initializing the sample controllers but didn’t have time to finish for this version. Maybe your calculations use the same variable names that the new script uses (and your initial values are being overwritten)? Have you tried running the model using the old Read_FAST_Input.m file with FAST v7.00.00? I think it should still work in your case.

Thanks for the suggestion. I was using the variable name, GenEff, in my simsetup file. Using the old Read_FAST_Input.m file with FAST v7 fixes the issue. The new version of FAST is working great and has substantially increased my productivity with the fix of the memory leak issue.